the 4 wire.red for ignition +12v,orange for +12v battery,black for grounding and white for tacho input. The 2 wire socket for shifting light.Becoz it using led type be sure you connect this 2 wire correctly.Otherwise it won't light....
sorry for the mistake.......
the idea came when changing new bumper .. noticed that be4 tis using promote bumper my engine will cooling quicker compare current bumper (special edition). Maybe the design itself...